The present invention relates to a headed screw construction wherein the shank of the screw locates in transverse anchor holes of an intramedullary nail and wherein threads on the shank of the screw are adapted for anchorage in bone.
The use of screw threads to fix or to anchor an intramedullary nail is known from EP 306,709 A2. In that case, an elongate screw is threaded for the entire length of its shank and passes through the intramedullary nail.
Screws having a shank with external threads only over a part of their length are known from U.S. Pat. No. 4,463,753. In that case, the two spaced regions of screw threads on the same shank serve to provide a compressive action, bringing together two fracture-separated parts of a bone. Threaded advance for the respective spaced thread regions is in the same direction, but with differing pitch. This prior art screw has no relation to an intramedullary nail.